This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A076431 #4 Mar 31 2012 14:39:53 %S A076431 9,16,36,128,144,256,361,529,1024,1369,1764,2209,2809,3136,3481,5041, %T A076431 5929,6889,8281,9409,10816,12321,13924,16900,17689,19881,22201,24649, %U A076431 27225,29929,33124,36100,39601,43264,51076,55225,59536,64009,69169 %N A076431 Perfect powers for which the two closest perfect powers are smaller. %e A076431 The two closest perfect powers to 9 are 8 (difference = 1) and 4 (difference =5). The third closest is 16 (difference = 7). Both 8 and 4 are smaller than 9, so 9 is in the list. %Y A076431 Cf. A001597, A053289, A075772, A076432, A076433. %K A076431 nonn %O A076431 1,1 %A A076431 _Neil Fernandez_, Oct 10 2002